무효전력을 이용한 태양광 PCS의 계통전압 제어

The voltage fluctuation is one of grid instability problems caused by a high penetration level of decentralized generating units such as photovoltaic (PV) systems. The reverse load flow by PV systems may lead to a grid voltage fluctuation and increases a risk of overvoltage in times of high solar irradiation. The grid voltage regulation of a PV power conditioning system (PCS) using reactive power is presented in this paper. The influence of reactive power supply by the PV system on the grid voltage is explained and the regulation capability of PCS is discussed. The performance and feasibility of presented method is verified by both simulation and experimental results. The results show that the concept described in this paper can be utilized to keep the grid voltage in its nominal range.